Investment Securities - Schedule of Amortized Cost, Allowance for Credit Losses and Fair Value (Details) - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Investment Securities
Amortized cost	$ 1,482,841,000	$ 1,679,397,000
Gross unrealized gains	1,066,000	585,000
Gross unrealized losses	(56,956,000)	(141,974,000)
Allowance for credit losses on investments	0	0
Fair Value	1,426,951,000	1,538,008,000
U.S. government agency securities
Investment Securities
Amortized cost	656,685,000	564,752,000
Gross unrealized gains	31,000	172,000
Gross unrealized losses	(3,519,000)	(1,917,000)
Allowance for credit losses on investments	0	0
Fair Value	653,197,000	563,007,000
Mortgage-backed securities - residential
Investment Securities
Amortized cost	619,439,000	927,883,000
Gross unrealized gains	511,000	393,000
Gross unrealized losses	(32,363,000)	(117,277,000)
Allowance for credit losses on investments	0	0
Fair Value	587,587,000	810,999,000
Mortgage-backed securities - commercial
Investment Securities
Amortized cost	11,201,000	15,965,000
Gross unrealized gains	8,000	0
Gross unrealized losses	(528,000)	(1,108,000)
Allowance for credit losses on investments	0	0
Fair Value	10,681,000	14,857,000
Municipal securities
Investment Securities
Amortized cost	185,472,000	169,498,000
Gross unrealized gains	480,000	20,000
Gross unrealized losses	(20,541,000)	(21,661,000)
Allowance for credit losses on investments	0	0
Fair Value	165,411,000	147,857,000
U.S. Treasury securities
Investment Securities
Amortized cost	7,061,000	299,000
Gross unrealized gains	19,000	0
Gross unrealized losses	0	0
Allowance for credit losses on investments	0	0
Fair Value	7,080,000	299,000
Corporate securities
Investment Securities
Amortized cost	2,983,000	1,000,000
Gross unrealized gains	17,000	0
Gross unrealized losses	(5,000)	(11,000)
Allowance for credit losses on investments	0	0
Fair Value	$ 2,995,000	$ 989,000